Method for manufacturing an electronic device

ABSTRACT

A method of manufacturing an electronic device, including the successive steps of: a) performing an ion implantation of indium or of aluminum into an upper portion of a first single-crystal gallium nitride layer, to make the upper portion of the first layer amorphous and to preserve the crystal structure of a lower portion of the first layer; and b) performing a solid phase recrystallization anneal of the upper portion of the first layer, resulting in transforming the upper portion of the first layer into a crystalline indium gallium nitride or aluminum gallium nitride layer.

This application claims the priority benefit of French Patentapplication number 18/58391, which is herein incorporated by reference.

TECHNICAL BACKGROUND

The present disclosure generally concerns light-emitting devices basedon semiconductor materials and methods of manufacturing the same. Itmore particularly aims at a method of manufacturing a light-emittingdevice based on indium gallium nitride (InGaN) or on aluminum galliumnitride (AlGaN).

PRIOR ART

A light-emitting device conventionally comprises one or a plurality oflight-emitting cells capable of converting an electric signal into alight radiation. Each light-emitting cell may comprise a stack of afirst semiconductor layer of a first conductivity type electricallyconnected to an anode or cathode electrode of the cell, of an activelayer, and of a second doped semiconductor layer of the secondconductivity type electrically connected to a cathode or anode electrodeof the cell. In operation, an electric current is applied between thefirst and second semiconductor layers of the cell. Under the effect ofthis current, the active layer emits a light radiation in a wavelengthrange which essentially depends on its composition.

Light-emitting cells where the active layer comprises one or a pluralityof InGaN layers or one or a plurality of AlGaN layers have in particularbeen provided. In such cells, the emission wavelength particularlydepends on the indium concentration in the InGaN layers of the activelayer or on the aluminum concentration in the AlGaN layers of the activelayer. More particularly, in light-emitting cells based on InGaN, theemission wavelengths shifts from blue to red when the indiumconcentration in the InGaN layers of the active layer increases.Similarly, in light-emitting cells based on AlGaN, the emissionwavelengths shifts from blue to ultraviolet when the aluminumconcentration in the AlGaN layers of the active layer increases.

An issue which arises is that, in known methods of manufacturinglight-emitting cells based on InGaN or on AlGaN, the increase of theindium concentration in the InGaN layers of the active layer or of thealuminum concentration in the AlGaN layers of the active layer causes adegradation of the crystalline quality of the active layer, whichresults in degrading the cell performance. Such a limitationparticularly results from lattice parameter mismatches between the InGaNor AlGaN layers of the active layer and an underlying base layer,generally made of gallium nitride (GaN), which mismatches are all thegreater than the indium concentration in the InGaN layers of the activelayer or the aluminum concentration in the AlGaN layers of the activelayer is high.

Thus, although it is theoretically possible, in light-emitting cellsbased on InGaN, to cover the entire visible spectrum by adapting theindium concentration in the InGaN layers of the active layer, it is inpractice difficult, or even impossible, to manufacture high-performancedevices having a high indium concentration in the InGaN layers of theactive layer. As a result, part of the theoretically available spectrumremains inaccessible in practice. Similarly, although it istheoretically possible, in light-emitting cells based on AlGaN, to covera large spectrum ranging from blue to ultraviolet by adapting thealuminum concentration in the AlGaN layers of the active layer, it is inpractice difficult, or even impossible, to manufacture devices having ahigh aluminum concentration in the AlGaN layers of the active layer orin the charge carrier injection layers surrounding the active layer, sothat a portion of the theoretically available spectrum remains inpractice inaccessible.

SUMMARY

Thus, an embodiment provides an electronic device manufacturing method,comprising the successive steps of:

-   -   a) performing an ion implantation of indium or of aluminum into        an upper portion of a first single-crystal gallium nitride        layer, to make the upper portion of the first layer amorphous        and to preserve the crystal structure of a lower portion of the        first layer; and    -   b) performing a solid phase recrystallization anneal of the        upper surface of the first layer, resulting in transforming the        upper portion of the first layer into a crystalline indium        gallium nitride or aluminum gallium nitride layer.

According to an embodiment, the method further comprises, after step b),a step c) of deposition, by vapor phase epitaxy, on the upper surface ofthe first layer, of a light-emitting structure comprising:

-   -   a doped semiconductor layer of a first conductivity type coating        the upper surface of the first layer;    -   an active layer coating the upper surface of the first        conductivity type; and    -   a doped semiconductor layer of the second conductivity type        coating the upper surface of the active layer.

According to an embodiment, during steps a) and b), a protection layercovers the upper surface of the first layer.

According to an embodiment, during step a), the implantation conditionsare selected so that the lower portion of the first layer has athickness smaller than one fifth of the thickness of the first layer.

According to an embodiment, during step a), a complementary implantationof nitrogen is performed to compensate for the indium or aluminum inputin the upper portion of the first layer.

According to an embodiment, the implantation energies are selected sothat the indium and nitrogen or aluminum and nitrogen concentrationprofiles are substantially superimposed at the interface between theupper portion and the lower portion of the first layer.

According to an embodiment, at step b), the solid phaserecrystallization anneal is carried out at a temperature in the rangefrom 300 to 1,200° C.

According to an embodiment, during steps a) and b), the first layerrests on an insulating layer itself resting on a support substrate.

According to an embodiment, step a) comprises a first step of ionimplantation of indium or of aluminum on first and second portions ofthe surface of the first layer, followed by a second step of ionimplantation of indium or of aluminum located on the second portion onlyof the surface of the first layer.

According to an embodiment, step c) is simultaneously carried out on thefirst and second portions of the surface of the first layer.

According to an embodiment, the electronic device is a light-emittingdevice.

According to an embodiment, the electronic device is a photoelectricconversion device.

According to an embodiment, the electronic device is a HEMT transistor.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features and advantages will be discussed indetail in the following non-limiting description of specific embodimentsin connection with the accompanying drawings, in which:

FIG. 1 shows a step of an example of a light-emitting devicemanufacturing method according to a first embodiment;

FIG. 2 shows another step of an example of a light-emitting devicemanufacturing method according to the first embodiment;

FIG. 3 shows another step of an example of a light-emitting devicemanufacturing method according to the first embodiment;

FIG. 4 shows another step of an example of a light-emitting devicemanufacturing method according to the first embodiment;

FIG. 5 shows another step of an example of a light-emitting devicemanufacturing method according to the first embodiment;

FIG. 6 shows another step of an example of a light-emitting devicemanufacturing method according to the first embodiment;

FIG. 7 shows a step of an example of a light-emitting devicemanufacturing method according to a second embodiment;

FIG. 8 shows another step of an example of a light-emitting devicemanufacturing method according to the second embodiment;

FIG. 9 shows another step of an example of a light-emitting devicemanufacturing method according to the second embodiment;

FIG. 10 shows another step of an example of a light-emitting devicemanufacturing method according to the second embodiment;

FIG. 11 shows another step of an example of a light-emitting devicemanufacturing method according to the second embodiment; and

FIG. 12 shows another step of an example of a light-emitting devicemanufacturing method according to the second embodiment.

DESCRIPTION OF THE EMBODIMENTS

The same elements have been designated with the same reference numeralsin the different drawings. In particular, the structural and/orfunctional elements common to the different embodiments may bedesignated with the same reference numerals and may have identicalstructural, dimensional, and material properties.

For clarity, only those steps and elements which are useful to theunderstanding of the described embodiments have been shown and aredetailed. In particular, the exact composition and the method ofmanufacturing the active layers of the described light-emitting deviceshave not been detailed, the described embodiments being compatible withusual embodiments of such active layers of light-emitting devices basedon InGaN or on AlGaN, provided to make the adaptations which may benecessary, which are within the abilities of those skilled in the art.Further, the forming of contacting metallizations on the anode andcathode semiconductor layers of the light-emitting cells and of possibleperipheral insulation structures separating neighboring light-emittingcells has not been detailed, the described embodiments being compatiblewith the usual forming of such elements.

Throughout the present disclosure, the term “connected” is used todesignate a direct electrical connection between circuit elements withno intermediate elements other than conductors, whereas the term“coupled” is used to designate an electrical connection between circuitelements that may be direct, or may be via one or more other elements.

In the following description, when reference is made to terms qualifyingabsolute positions, such as terms “front”, “rear”, “top”, “bottom”,“left”, “right”, etc., or relative positions, such as terms “above”,“under”, “upper”, “lower”, etc., or to terms qualifying directions, suchas terms “horizontal”, “vertical”, etc., unless otherwise specified, itis referred to the orientation of the drawings, it being understoodthat, in practice, the described devices may be oriented differently.

The terms “about”, “approximately”, “substantially”, and “in the orderof” are used herein to designate a tolerance of plus or minus 10%,preferably of plus or minus 5%, of the value in question.

FIGS. 1 to 6 are cross-section views illustrating successive steps of anexample of a light-emitting device manufacturing method according to afirst embodiment.

FIG. 1 illustrates an initial structure comprising a support substrate101, for example, made of sapphire or of silicon, an insulating layer103, for example, made of silicon oxide, coating the upper surface ofsupport substrate 101, and a single-crystal gallium nitride (GaN) layer105 coating the upper surface of layer 103. The lower and upper surfacesof insulating layer 103 are for example in contact respectively with theupper surface of substrate 101 and with the lower surface of GaN layer105.

The stack of FIG. 1 may be obtained by a transfer method comprising:

-   -   forming single-crystal GaN layer 105, for example, by vapor        phase epitaxy, on a surface of a growth substrate (not shown);    -   forming a silicon oxide layer 103 a on the surface of GaN layer        105 opposite to the growth substrate (the lower surface of layer        105 in FIG. 1);    -   forming a silicon oxide layer 103 b on a surface (the upper        surface in FIG. 1) of support substrate 101;    -   transferring the assembly comprising the growth substrate, GaN        layer 105, and silicon oxide layer 103 a onto the assembly        comprising support substrate 101 and silicon oxide layer 103 b,        to place in contact and bond by direct gluing or molecular        bonding the surface of layer 103 a opposite to GaN layer 105 to        the surface of layer 103 b opposite to support substrate 101;        and    -   remove the growth substrate to free the access to the surface of        GaN layer 105 opposite to layer 103 a.

Preferably, the transfer method used to form the stack of FIG. 1 is amethod of SMART CUT (trade name) type, wherein:

-   -   a GaN layer initially formed on the growth substrate (not shown)        has a thickness greater than that of layer 105;    -   a buried hydrogen layer is implanted into the GaN layer from the        surface of the GaN layer opposite to the growth substrate; and    -   the removal of the growth substrate is performed by cleaving of        the initial GaN layer at the level of the buried hydrogen layer,        to only keep on the support substrate the portion of the GaN        layer arranged on the side of the buried hydrogen layer opposite        to the growth substrate (corresponding to layer 105 of the        structure of FIG. 1).

The use of a method of SMART CUT type has the advantage of enabling totransfer a relatively thin GaN layer 105, of high crystal quality andrelatively lightly strained, onto the upper surface of substrate 101.

As an example, the stack of FIG. 1 is obtained by a method similar tothe method described in the article entitled “Bridging the green gapwith a new foundation” of Amélie Dussaigne and David Sotta(www.compoundsemiconductor.net—July 2017), modified to replace thesingle-crystal InGaN donor substrate provided in the article with asingle-crystal GaN donor substrate.

In the above-described examples, intermediate insulating layer 103 isformed by the stack of layers 103 a and 103 b. As an example, layer 103has a thickness in the range from 100 nm to 1 μm, for example, in theorder of 500 nm. GaN layer 105 has, for example, a thickness in therange from 10 to 500 nm, and preferably from 20 to 100 nm. Layer 103 andlayer 105 for example extend continuously over substantially the entireupper surface of support substrate 101.

FIG. 2 illustrates a step of deposition of a protection layer 107 on theupper surface of GaN layer 105. Layer 107 is for example in contact withthe upper surface of GaN layer 105. Layer 107 for example extends oversubstantially the entire upper surface of GaN layer 105. Layer 107particularly has the function of preventing or of limiting theexodiffusion of nitrogen from GaN layer 105, and thus the breaking up ofthe GaN of layer 105, during a subsequent step of the recrystallizationanneal of layer 105 (FIG. 4). As an example, layer 107 is made ofsilicon nitride, for example, of Si₃N₄. The thickness of layer 107 isfor example in the range from 5 to 500 nm, and preferably from 10 to 50nm.

FIG. 3 illustrates a step of ion implantation of indium or of aluminumin GaN layer 105, through protection layer 107. The step of ionimplantation of FIG. 3 enables to introduce indium or aluminum into GaNlayer 105 to modify its composition to obtain an InGaN layer or an AlGaNlayer. The implantation energy and the implantation dose enable todefine the concentration profile of the new alloy. During this step, acomplementary ion implantation of nitrogen may be provided to compensatefor the indium or aluminum input and keep the stoichiometry across thedepth of the new formed alloy. The implantations energies and doses areselected to obtain a full amorphization of an upper portion 105 a oflayer 105, and to keep the original crystal reference in a lower portion105 b of layer 105. Preferably, the thickness of the lower referencesingle-crystal layer 105 b is relatively small to enable to carry offpossible dislocations or other crystal defects during a subsequent stepof recrystallization anneal of layer 105 a. As an example, the thicknessof the lower reference single-crystal layer 105 b is smaller than halfthe thickness of original layer 105, for example smaller than one fifthof the thickness of original layer 105. As an example, the thickness oflower reference single-crystal layer 105 b is in the range from 2 to 100nm, preferably from 2 to 10 nm. As an example, the implantation energiesare selected so that the nitrogen and indium or nitrogen and aluminumconcentration profiles are substantially superimposed at the interfacebetween lower single-crystal portion 105 b and upper amorphous portion105 a of layer 105, to define a clear interface between crystal layer105 b and amorphous layer 105 a.

FIG. 4 illustrates a step of anneal of the structure obtained at the endof the steps of FIGS. 1 to 3, to obtain a solid phase recrystallizationof the upper portion 105 a of layer 105. The anneal is for exampleperformed at a temperature in the range from 300 to 1,200° C., forexample, from 400 to 1,000° C. The duration of the recrystallizationanneal is for example in the range from 1 minute to 10 hours. As anexample, the anneal is performed at approximately 400° C. forapproximately 1 hour. During this step, a recrystallization of InGaN orAlGaN layer 105 a is obtained. The crystal reference is provided by theunderlying single-crystal GaN layer 105 b. The proportion of indium orof aluminum of the new crystal layer 105 a is defined by the ionimplantation doses provided at the previous step.

FIG. 5 illustrates a step of removal of protection layer 107 to free theaccess to the upper surface of crystalline InGaN or AlGaN layer 105 a.

FIG. 6 illustrates a step of resumption of the growth, for example, byvapor phase epitaxy, from the upper surface of layer 105 a, to form theactual light-emitting structure. As an example, the step of FIG. 6comprises a step of epitaxial growth of a first doped semiconductorlayer 109 of a first conductivity type, for example, type N, on theupper surface of layer 105 a, followed by a step of epitaxial growth ofan emissive active layer 111 on the upper surface of layer 105 a,followed by a step of epitaxial growth of a doped semiconductor layer113 of the second conductivity type, for example, of type P, on theupper surface of active layer 111. Layer 109 is for example in contactwith the upper surface of layer 105 a. Active layer 111 is for examplein contact with the upper surface of layer 109. An electron barrierlayer (not shown in FIG. 6) may form an interface between active layer111 and layer 113. Layer 109 is for example made of an alloy of InGaN orof AlGaN having the same composition as layer 105 a, but N-type doped.Active layer 111 for example comprises confinement means correspondingto multiple quantum wells. As an example, active layer 111 is formed ofan alternation of semiconductor layers of a first material and ofsemiconductor layers of a second material, each layer of the firstmaterial being sandwiched between two layers of the second material, thefirst material having a narrower bandgap than that of the secondmaterial, to define multiple quantum wells. In the case where layer 105a is made of InGaN, the first material may be InGaN and the secondmaterial may be GaN or InGaN having an indium concentration smaller thanthat of the first material. In the case where layer 105 a is made ofAlGaN, the first material may be AlGaN and the second material may beAlGaN having an aluminum concentration greater than that of the firstmaterial. Layer 113 is for example a P-type doped InGaN layer in thecase where layer 105 a is made of InGaN or a P-type doped AlGaN layer inthe case where layer 105 a is made of AlGaN.

According to the type of light-emitting device which is desired to beformed (individually-controllable multiple cell image display device,illumination device with multiple cells connected in series or inparallel, single-cell illumination device, etc.) a subsequent step (notshown) of etching vertical trenches of singularization of light-emittingcells, particularly crossing layers 113 and 111 of the structure of FIG.6, may be provided. As a variation, the singularization of theelementary cells of the device may be achieved before the step of FIG. 6of epitaxial growth of the light-emitting structure. For this purpose,vertical singularization trenches may for example be etched in layer105, after the recrystallization anneal of upper portion 105 a of layer105 and before the deposition steps of FIG. 6.

An advantage of the method described in relation with FIGS. 1 to 6 isthat the steps of ion implantation (FIG. 3) and of solid phaserecrystallization anneal (FIG. 4) enable to adjust the indium oraluminum concentration in layer 105 a used as a base for the epitaxialgrowth of the actual light-emitting structure (that is, the stackcomprising layers 109, 111, and 113). In particular, this methodenables, starting from a single-crystal GaN layer 105, to obtain acrystalline InGaN layer 105 a having a relatively high indiumconcentration, for example, greater than 10%, or a crystalline AlGaNlayer 105 a having a relatively high aluminum concentration, forexample, greater than 50%. The indium or aluminum concentration of basecrystal layer 105 a may in particular be selected to be close to theindium or aluminum concentration of the InGaN or AlGaN layers of activelayer 111. This enables, during subsequent steps of epitaxial growth ofthe actual light-emitting structure, to obtain a good crystal quality ofthe deposited layers and particularly of active layer 111, includingwhen the indium or aluminum concentration of the layers of thelight-emitting structure is high.

In particular, in the case of the manufacturing of a light-emittingdevice based on InGaN, this is a significant advantage over the methodsdescribed in the above-mentioned article “Bridging the green gap with anew foundation”, and in the article entitled “Enhanced In incorporationin full InGaN heterostructure grown on relaxed InGaN pseudo-substrate”of A. Even et al. (Applied Physics Letters 110, 262103 (2017)), wherethe epitaxial growth of the light-emitting structure is performed from asingle-crystal InGaN substrate formed by vapor phase epitaxy, having anindium concentration which remains low (in the order of 4%).

Another advantage of the above-described method is that, since thecomposition of base layer 105 a is adjusted ex post facto, byimplantation and solid phase recrystallization, light-emitting cellshaving their base layers 105 a exhibiting different indium or aluminumconcentrations may be formed from a same original single-crystal layer105, which is not possible with the methods described in theabove-mentioned articles.

FIGS. 7 to 12 are cross-section views illustrating successive steps ofan example of a method of manufacturing a light-emitting deviceaccording to a second embodiment.

In the second embodiment, it is desired to form a light-emitting devicecomprising a plurality of light-emitting cells capable of emitting indifferent wavelength ranges. An embodiment of a device based on InGaNcomprising a first cell B capable of mainly emitting blue light, forexample, in a wavelength range from 400 to 490 nm, a second cell Gcapable of mainly emitting green light, for example, in a wavelengthrange from 490 to 570 nm, and a third cell R capable of mainly emittingred light, for example, in a wavelength range from 570 to 710 nm, willmore particularly be described hereafter. It will be within theabilities of those skilled in the art to adapt this method to form anylight-emitting device based on InGaN or on AlGaN comprising at least twocells capable of emitting in different wavelength ranges.

FIG. 7 illustrates a first implantation step identical or similar tothat of FIG. 3. This step is preceded by steps (not shown again)identical or similar to the steps of FIGS. 1 and 2. During the step ofFIG. 7, the implanted indium corresponds to the dose necessary to formthe cell having the smallest indium concentration, that is, cell B inthe present example. As an example, the implanted indium dose isselected to obtain an indium concentration in the order of 5% in upperportion 105 a of layer 105. The first indium dose is implanted oversubstantially the entire surface of the device, that is, not only incell B, but also in cells G and R.

FIG. 8 illustrates a step of forming, for example, by deposition andetching, a first implantation mask 201 on the upper surface ofprotection layer 107. The function of mask 201 is to protect cell Bduring a second step of indium implantation into cells G and R. As anexample, mask 201 substantially covers the entire upper surface of cellB and does not cover the upper surface of cells G and R. Mask 201 is forexample formed by a silicon oxide layer, for example, having a thicknessin the range from 500 nm to 1 μm, for example, in the order of 600 nm,comprising local openings opposite cells G and R.

FIG. 8 further illustrates a second indium implantation step, similar tothe step of FIG. 7, but during which only cells G and R of the deviceare implanted into, cell B being protected by mask 201. During thisstep, the implanted indium dose corresponds to the dose necessary toform, taking into account the dose already implanted during the step ofFIG. 7, the cell having the second lowest indium concentration, that is,cell G in the present example. As an example, the indium dose implantedduring the step of FIG. 8 is selected to obtain an indium concentrationin the order of 10% in upper portion 105 a of layer 105 in cells G andR. As an example, the implantation doses and energies involved duringthe implantation step of FIG. 8 are substantially the same as during theimplantation step of FIG. 7.

FIG. 9 illustrates a step of forming, for example, by deposition andetching, a second implantation mask 203 on the upper surface of thestructure obtained at the end of the steps of FIGS. 7 and 8. Thefunction of mask 203 is to protect cell G during a third step of indiumimplantation into cell R. As an example, mask 203 substantially coversthe entire upper surface of cells B and G and does not cover the uppersurface of cell R. Mask 203 is for example made of the same material andsubstantially has the same thickness as mask 201.

FIG. 9 further illustrates a third indium implantation step, similar tothe implantation steps of FIGS. 7 and 8, but during which only cell R ofthe device is implanted into, cells B and G being protected by masks 201and 203. During this step, the implanted indium dose corresponds to thedose necessary to form, taking into account the doses already implantedduring the implantation steps of FIGS. 7 and 8, the cell having thehighest indium concentration, that is, cell R in the present example. Asan example, the indium dose implanted during the step of FIG. 9 isselected to obtain an indium concentration in the order of 15% in upperportion 105 a of layer 105 in cell R. As an example, the implantationdoses and energies involved during the implantation step of FIG. 9 aresubstantially the same as during the implantation steps of FIGS. 7 and8.

FIG. 10 illustrates a step of annealing the structure obtained at theend of the step of FIGS. 7 to 9, to obtain a solid phaserecrystallization of upper portion 105 a of layer 105. The anneal is forexample carried out in conditions identical or similar to what has beendescribed hereabove in relation with FIG. 4. During this step, arecrystallization of InGaN layer 105 a is obtained. The crystalreference is provided by the underlying single-crystal GaN layer 105 b.The proportion of indium or of aluminum of the new crystal layer 105 ais defined by the ion implantation doses provided during the previoussteps. Thus, the indium concentration in layer 105 a is higher in cell Rthan in cell G, and higher in cell G than in cell B.

FIG. 11 illustrates a step of removing, for example by etching,implantation masks 201 and 203 and of protection layer 107, to free theaccess to the upper surface of crystalline InGaN layer 105 a oversubstantially the entire surface of the device.

FIG. 11 further illustrates a step of etching, from the upper surface oflayer 105 a, vertical trenches 205 laterally delimiting and insulatingfrom one another cells B, G, and R of the device. In the shown example,trenches 205 entirely cross layer 105 and stop on the upper surface oflayer 103.

FIG. 12 illustrates a step of resumption of the growth, for example, byvapor phase epitaxy, from the upper surface of layer 105 a, to form thelight-emitting structures of cells B, G, and R. As an example, theforming of the light-emitting structures comprises, as in the example ofFIG. 6, a step of epitaxial growth of a first doped semiconductor layer109 of a first conductivity type, for example, of type N, on the uppersurface of layer 105 a, followed by a step of epitaxial growth of anemissive active layer 111 on the upper surface of layer 105 a, followedby a step of epitaxial growth of a doped semiconductor layer 113 of thesecond conductivity type, for example, type P, on the upper surface ofactive layer 111.

In this example, the light-emitting structures of cells B, G, and R areformed simultaneously, in the same vapor phase epitaxial growthconditions. Indeed, the sole fact for the indium concentration in seedlayer 105 a to be different in the different cells of the device enablesto obtain different indium concentrations in the active layers of thedifferent cells, and thus different emission wavelengths in thedifferent cells.

As a variation (not shown), rather than forming the trenches 205 ofsingularization of the different cells before the growth of thelight-emitting structures as described hereabove, the light-emittingstack may be continuously grown over the entire surface of the deviceand then, only after the growth of the light-emitting stack, verticaltrenches crossing layers 113, 111, and possibly layers 109 and 105,laterally delimiting and insulating cells B, G, and R of the device fromone another, may be etched.

Various embodiments and variations have been described. It will beunderstood by those skilled in the art that certain features of thesevarious embodiments and variations may be combined, and other variationswill occur to those skilled in the art. In particular, the describedembodiments are not limited to the numerical values mentioned as anexample in the description.

Further, although only embodiments of light-emitting devices have beendescribed herein, the described methods may be adapted to the forming ofphotodiodes, of HEMTs (“High Electron Mobility Transistors”) or, moregenerally, of any electronic component based on indium gallium nitrideor based on aluminum gallium nitride.

1. A method of manufacturing an electronic device, comprising thesuccessive steps of: a) performing an ion implantation of indium or ofaluminum into an upper portion of a first single-crystal gallium nitridelayer, to make the upper portion of the first layer amorphous and topreserve the crystal structure of a lower portion of the first layer;and b) performing a solid phase recrystallization anneal of the upperportion of the first layer, resulting in transforming the upper portionof the first layer into a crystalline indium gallium nitride or aluminumgallium nitride layer.
 2. The method of claim 1, further comprising,after step b), a step c) of deposition, by vapor phase epitaxy, on theupper surface of the first layer, of a light-emitting structurecomprising: a doped semiconductor layer of a first conductivity typecoating the upper surface of the first layer; an active layer coatingthe upper surface of the doped semiconductor layer of the firstconductivity type; and a doped semiconductor layer of the secondconductivity type coating the upper surface of the active layer.
 3. Themethod of claim 1, wherein, during steps a) and b), a protection layercovers the upper surface of the first layer.
 4. The method of any ofclaim 1, wherein, at step a), the implantation conditions are selectedso that the lower portion of the first layer has a thickness smallerthan one fifth of the thickness of the first layer.
 5. The method of anyof claim 1, wherein, during step a), the implantation conditions areselected so that the lower portion of the first layer has a thickness inthe range from 2 to 10 nm.
 6. The method of any of claim 1, wherein,during step a), a complementary implantation of nitrogen is performed tocompensate for the indium or aluminum input in upper portion of thefirst layer.
 7. The method of claim 6, wherein the implantation energiesare selected so that the indium and nitrogen or aluminum and nitrogenconcentration profiles are superimposed at the interface between theupper portion and the lower portion of the first layer.
 8. The method ofany of claim 1 wherein, at step b), the solid phase recrystallizationanneal is carried out at a temperature in the range from 300 to 1,200°C.
 9. The method of claim 1, wherein the solid phase recrystallizationanneal is carried out at approximately 400° C. for approximately 1 hour.10. The method of claim 1, wherein, during steps a) and b), the firstlayer rests on an insulating layer itself resting on a supportsubstrate.
 11. The method of claim 1, wherein step a) comprises a firststep of ion implantation of indium or of aluminum on first and secondportions of the surface of the first layer, followed by a second step ofion implantation of indium or of aluminum located on the second portiononly of the surface of the first layer.
 12. The method of claim 1,further comprising, after step b), a step c) of deposition, by vaporphase epitaxy, on the upper surface of the first layer, of alight-emitting structure comprising: a doped semiconductor layer of afirst conductivity type coating the upper surface of the first layer; anactive layer coating the upper surface of the doped semiconductor layerof the first conductivity type; and a doped semiconductor layer of thesecond conductivity type coating the upper surface of the active layer,wherein step a) comprises a first step of ion implantation of indium orof aluminum on first and second portions of the surface of the firstlayer, followed by a second step of ion implantation of indium or ofaluminum located on the second portion only of the surface of the firstlayer, wherein step c) is carried out simultaneously on the first andsecond portions of the surface of the first layer.
 13. The method of ofclaim 1, wherein the electronic device is a light-emitting device. 14.The method of any of claim 1, wherein the electronic device is aphotoelectric conversion device.
 15. The method of any of claim 1,wherein the electronic device is a HEMT transistor.